Step 4: Identifying functions as linear or nonlinear
As infants grow from a toddler to a young adult, there may be times when they are ill and medication is needed. It is extremely important that medication be administered in the exact dose so the child receives the correct amount. Too little or too much medication could have serious side effects. A popular children’s fever medicine manufacturer recommends the following dosage information to parents and pediatricians.

Children’s Fever Medicine
(given every 4–6 hours, as needed)
Weight 24+ lbs 36+ lbs 48+ lbs 60+ lbs 72+ lbs
Dosage 5 mL 7.5 mL 10 mL 12.5 mL 15 mL

a) Evaluate the data and find the rate of change from one age group to the next. Explain how you found the rate of change. (2 points)

b) Is the relationship between weight and the amount of medicine linear? Explain. (2 points)